KR101645260B1 - System and Method for synchronizing data including timestamp between plural controllers - Google Patents

Abstract

The present invention relates to a control system of a robot, and more particularly, to a synchronization method comprising a plurality of servers and a client structure for transferring data in a plurality of control periods, and a data synchronization System and method.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a system and method for synchronizing data including precise time recording of a plurality of control periods,

The present invention relates to a control system of a robot, and more particularly, to a synchronization method comprising a plurality of servers and a client structure for transferring data in a plurality of control periods, and a data synchronization System and method.

Generally, there is a method of synchronizing data in a control system of a robot, in which a change of data is tracked to update the changed data item. This method requires a process of storing and analyzing the log of the change of the software process with respect to the data item and the change of the data item, which requires a certain processing time.

Another technique is to synchronize data through a centralized processing in a gateway server located in a plurality of nodes. This approach is handled in the order that the server receives data from the individual nodes, processes the update of the data in the server, and sends the data back to the individual nodes. Therefore, if the server is overloaded or malfunctions, the entire data synchronization becomes impossible.

In other words, the method of receiving and updating all the data from a single centralized server can be reliably updated for the same data item, but if the server is overloaded or malfunctioned, the entire data can not be synchronized have.

 Prior art related to timestamp is a method of calculating a time record by measuring a delay time of a packet while exchanging data packets among a plurality of nodes through a network. This method measures the relative delay time for each node, so that all nodes can not have the same exact time reference.

1. Korean Patent Publication No. 10-2006-0126839 2. Korean Patent Publication No. 10-2007-0052729

Disclosure of Invention Technical Problem [8] The present invention has been proposed in order to solve the above problems, and it is an object of the present invention to provide a data synchronization system and method for synchronizing data separated by a unique identifier by executing a server process and a client process for each controller in a plurality of controllers The purpose is to provide.

It is another object of the present invention to provide a data synchronization system and method for obtaining precise time stamps.

In order to achieve the above object, the present invention provides a data synchronization system in which a server process and a client process are executed for individual controllers in a plurality of controllers, and data items separated by unique identifiers are synchronized with each other.

The data synchronization system comprising:

A data synchronization system comprising a time record for synchronizing data between a plurality of sensors disposed in a robot,

An external electronic circuit for generating a synchronizing signal; And

A plurality of controllers for generating time records in accordance with the time information of the synchronization signal or the own operating system and for synchronizing data with the time recording and unique identifier through communications between the server process and the client processor and updating the data according to the synchronization, ; And

At this time, the plurality of controllers simultaneously receive the synchronization signal and synchronize the reference point of the time recording.

The communication between the server process and the client process may be a communication between one client process and a plurality of server processes.

The synchronization signal may be an analog waveform of a triangular wave.

In addition, the plurality of controllers may acquire the time information of the self-operating system separately for a time longer than a second unit, and acquire the time information for a time shorter than a second unit using the synchronization signal.

In addition, the second unit may be characterized by being 1 second.

The correction of the time recording may be performed using the start point of the period of the synchronization signal.

The starting point of the period of the synchronizing signal may be a clock value calculated using a voltage magnitude, a rising and a falling of the waveform of the synchronizing signal.

The correction of the time recording may be a value obtained by converting the difference between the clock value of the start point and the current clock value of the corresponding controller among the plurality of controllers into a time.

Further, the plurality of controllers may be configured to acquire the time record on the same time axis.

The connection relationship between the server process and the client process may be defined as a connection configuration file including a server list, a server address according to the server list, and data item information.

In addition, the plurality of controllers may be configured to execute only one server process and one client process, respectively.

The unique identifier may be assigned to each of the plurality of controllers and data items.

According to another aspect of the present invention, there is provided a data synchronization method of a data synchronization system including a time record for synchronizing data between a plurality of sensors disposed in a robot, the method comprising: generating an external electronic circuit by generating a synchronization signal; A plurality of controllers generating a time record according to the time information of the synchronization signal or the operating system; The plurality of controllers generating data having the time stamp and unique identifier; Synchronizing the plurality of controllers with each other through communication between a server process and a client processor; And updating the data according to the synchronization by the plurality of controllers. The method of synchronizing data includes time recording.

According to the present invention, in synchronizing and updating the data, the update time is shortened by overwriting in units of data blocks including a unique identifier (Identifier) and a time stamp (Timestamp) without overlapping.

Another effect of the present invention is to execute a server and a client process for individual nodes to synchronize and transfer data separated by a unique identifier, and even if some of the nodes lose their functions, data synchronization between other nodes continues This is possible.

In other words, there is no gateway server required for data validation and centralized processing, and the controllers are interconnected to enable stable operation, and the data includes unique identifiers for individual controllers and items, Synchronization processing is possible.

Another effect of the present invention is that the same signal source such as a rectangular waveform and a triangular waveform output from a single external electronic circuit can be received from a plurality of controllers and time recording calculated on the same basis can be used. Further, in order to mix various sensor information in the robot system, it is necessary to have the same time base reference as possible, and using the method of obtaining precise time recording proposed in the present invention, time recording expressed in precision of about 10 milliseconds or less can be used .

1 is a conceptual diagram of a data synchronization system 100 showing a structure for processing data including precise timestamps of a plurality of control periods according to an embodiment of the present invention.
FIG. 2 is a flow chart showing a process of a server process, which is a control period data processing procedure shown in FIG. 1. FIG.
3 is a flow chart showing a client process process as a control period data processing procedure shown in FIG.
4 is a waveform diagram showing the concept of acquiring the control period time stamp shown in Fig.
5 to 7 are conceptual diagrams showing a procedure for obtaining a precise time stamp.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

1 is a conceptual diagram of a data synchronization system 100 showing a structure for processing data including precise timestamps of a plurality of control periods according to an embodiment of the present invention. Referring to FIG. 1, the data synchronization system 100 is for synchronizing data between a plurality of sensors (not shown) disposed in a robot (not shown). To this end, the data synchronization system 100 comprises an external electronic circuit (not shown) for generating a synchronization signal and a time record in accordance with the time information of the synchronization signal or its operating system, First to Nth controllers 110-1 to 110-N for synchronizing the data with each other through communication between the server process and the client processor and updating the data according to the synchronization.

Within the first to Nth controllers 110-1 to 110-N, a server process 111 and a client process 112 are configured, respectively. These server processes 111 and client processes 112 are connected in a server-client communication manner.

Of course, the connection relationships between the plurality of server processors 111 and the client processes 112 are defined in advance as connection establishment files. Therefore, when the server processor 111 and the client process 112 are executed, they are connected to each other through this connection configuration file.

The connection setting file contains a server list (ServerList), a server address (Address), and data item information (DataList) according to the server list in order to define the connection relationship between the server process and the client processes.

The connection configuration file may be an eXtensible Markup Language (XML) file format, but is not limited thereto, and other file formats such as hyper text markup language (HTML) and hyper text markup language (HTML) are also available. An example of a connection configuration file created in XML is as follows.

<? xml version = "1.0" encoding = "UTF-8">

<Configuration>

        <ServerList>

                <Server isConnect = "true">

                        <ID> SBC3 </ ID>

                        <Address> 10.0.0.3 </ Address>

                        <DataList>

                                <Data name = "DepthSensor" type = "double" array = "none" length = "8" />

                                <Data name = "Sonar" type = "float" array = "256" length = "1024" />

                        </ DataList>

                </ Server>

        </ ServerList>

</ Configuration>

1, the communication between the server process 111 and the client process 112 is a communication between one client process and a plurality of server processes.

The first to Nth controllers 110-1 to 110-N include a controller for performing a function of a robot, a controller for collecting environmental information, and a controller for executing an operation algorithm.

Such a plurality of controllers requires mutual exchange of function inputs for the collaboration and data of the function outputs with the same time base. In particular, these controllers constitute an underwater robot control system.

In particular, the first to Nth controllers 110-1 to 110-N individually acquire from the time information of the controller's own operating system in the case of a time in units of seconds or more. If the time is less than a second, a synchronous signal generated from an external electronic circuit (not shown) is received and acquired.

In this case, the first to Nth controllers 110-1 to 110-N simultaneously receive the synchronization signal to synchronize the reference points of time recording.

In addition, the plurality of controllers 110-1 to 110-N may acquire the time record on the same time axis. A diagram showing the concept of acquiring such a timestamp is shown in Figs. 4-7. This will be described later.

1, the server process 111 and the client process 112 are executed for the individual controllers in the first to Nth controllers 110-1 to 110-N, Synchronize. In other words, generally, a method of receiving and updating all data from a single centralized server can reliably update the same data item, but if the function of the server is overloaded or malfunctioning, the entire data can not be synchronized There is a problem.

In order to solve this problem, in one embodiment of the present invention, unique identifiers are assigned to individual controllers and data items in the entire system to which a plurality of controllers 110-1 to 110-N are connected so that they are not overlapped.

Also, one server process and one client process are executed in the individual controllers 110-1 to 110-N, and the data items in the controller are transmitted to and received from a plurality of controllers. One server process is connected to a client process of a plurality of other controllers, and one client process is connected to a server process of a plurality of other controllers.

In other words, there is one server process 111 and one client process 112 in the individual controller, and the server process 111 holds the data item held by the corresponding controller, receives the client process request from the other controller, It plays a role.

The client process 112 connects to each server process executed by the controller other than the controller, and fetches a data item. The server process 111 and the client process 112 are periodically executed to perform a synchronization function. The connection relationship between the server and the client process in the plurality of control periods is defined by the above-described connection configuration file (XML, etc.), and the relationship is controlled.

Therefore, even if some of the controllers stop functioning, synchronization of data is continuously possible between the other controllers.

FIG. 2 is a flow chart showing a process of a server process, which is a control period data processing procedure shown in FIG. 1. FIG. Referring to FIG. 1, when a server process is executed in the first to Nth controllers 110-1 to 110-N, a data update thread execution and a client request processing thread execution are performed (steps S210, S220, S230) .

When the data update thread is executed, a memory area allocation for storing data to be synchronized is performed, and it is confirmed whether this operation is repeated periodically (steps S221 and S223).

As a result of checking, if it is not periodically repeated, execution of the data update thread is terminated (step S229).

Alternatively, if it is periodically repeated in step S223, a current timestamp and a data value are acquired, and data is updated in the memory area (steps S225 and S227). Thereafter, the process proceeds to step S223.

On the other hand, when the client request processing thread is executed, the client process of the other controller is connected, and it is confirmed whether the job is periodically repeated (steps S231 and S233).

As a result of checking, if it is not periodically repeated, the execution of the client request processing thread is terminated (step S239).

Otherwise, if it is periodically repeated in step S233, the data item is requested and data including the current time record is transmitted (steps S235 and S237). Thereafter, the flow proceeds to step S233.

Meanwhile, there is a process of confirming whether the server process is terminated during the execution of the client request processing thread, and the server process is terminated or the server process is continuously executed according to the confirmation result (steps S240 and S241).

3 is a flow chart showing a client process process as a control period data processing procedure shown in FIG. Referring to FIG. 3, when the client process is executed in the first to Nth controllers 110-1 to 110-N, the connection setting file is read (steps S310 and S320).

The server list is obtained through the connection setting file, and the server address and the data item information are parsed to execute thread execution for each server connection (steps S340 and S350).

When a thread is executed for each server connection, a memory area is allocated and initialized for the data item, and it is confirmed whether this operation is repeated periodically (steps S330 and S331).

If it is determined that the connection is not periodically repeated, the thread for connection to the server is terminated (step S337).

Otherwise, if it is periodically repeated in step S331, a data item is requested to the server process of another controller, and the data is received in the server process and updated in the memory area (steps S333 and S335). Thereafter, the process proceeds to step S331.

Meanwhile, there is a process of confirming whether the server process is terminated during thread execution for each server connection. The server process is terminated or the server process is continuously executed according to a result of the check (steps S360 and S370).

4 is a waveform diagram showing the concept of acquiring the control period time stamp shown in Fig. That is, it is a waveform diagram showing a concept of obtaining a precise time stamp (Timestamp).

In other words, the first to Nth controllers 110-1 to 110-N simultaneously receive the signal source (i.e., the synchronization signal) periodically outputted from the external electronic circuit 410 located at the outside of the time, Synchronize reference points.

The signal source of the external electronic circuit 410 located outside is generated in a cycle of 1 second or less. The individual controllers 110-1 to 110-N acquire the time in units of seconds or more from the time information of the operating system of the controller itself and the time in seconds or less to acquire and calculate the synchronization signal of the external electronic circuit 410 .

The synchronous signal of the external electronic circuit 410 has an analog waveform of a triangular wave and even when a plurality of controllers 110-1 to 110-N receives a synchronous signal at different points on the time axis, / Desc / Clms Page number 16 &gt; shape of the periodic signal. This will be described later with reference to Figs. 5 to 7.

4, the In-System Reprogrammable (ISR) of each controller 110-1 through 110-N is executed at non-periodic intervals, and two or more external electronic circuits 410 (Voltage magnitude, up / down), and the zero point reference is adjusted to the value calculated for each controller.

5 to 7 are conceptual diagrams showing a procedure for obtaining a precise time stamp. 5-7, the basic timestamp uses the system time of the controller (i.e., the operating system's time information), which has an accuracy of 10 milliseconds or more. The external electronic circuit (410 in FIG. 4) generates a synchronizing signal in which the analog voltage of the triangular waveform changes at a cycle of 50 Hz and inputs it to the controllers 110-1 to 110-N.

Then, the first to Nth controllers 110-1 to 110-N perform a first analog-to-digital conversion (ADC) of the voltage of the synchronization signal and obtain the clock value of the current controller. In other words, the digital converted voltage value is determined according to the ADC bit, and if 12 bit resolution, 2 ¹² = 4096 and an integer value between 0 and 4095.

 The time recording has a delay time of about 1 millisecond. The measurement of the delay time is obtained by the difference of the clock value (Clock Count) of the controller before and after the delay. In other words, the actual time for one clock is determined for each CPU of the controller.

Thereafter, the controllers 110-1 to 110-N perform a second analog-to-digital conversion of the voltage of the synchronization signal and obtain the current system clock value.

Accordingly, calculating the difference between the first measured voltage and the second measured voltage and dividing the difference by the delay time results in the slope of the synchronizing signal of the external electronic circuit. Since the period and the waveform of the synchronizing signal input from the external electronic circuit are known in advance, the time point of the primary measurement is estimated by comparing the slope values.

Referring to FIG. 5, if the absolute value of the calculated slope is equal to the absolute value of the slope of the synchronizing signal waveform, and the sign is positive, the primary / secondary measurement time point is in the rising state of the waveform.

Referring to FIG. 6, if the absolute value of the calculated slope is equal to the absolute value of the slope of the synchronous signal waveform and the sign is negative, the primary / secondary measurement time point is in the rising state of the waveform.

Referring to FIG. 7, if the absolute value of the calculated slope is not equal to the absolute value of the slope of the synchronizing signal waveform, the first measuring point is in the rising state of the waveform and the second measuring point is in the falling state of the waveform.

Then, a clock value (Clock Count) of the controllers 110-1 to 110-N corresponding to the start point of the cycle of the external synchronization signal is obtained. The equation is expressed as follows.

는 동기 신호의 주기의 시작점에 해당하는 클럭값이다.
Here, (X, Y) represents the clock value and the voltage magnitude in the primary or secondary measurement, and? Represents the measured slope value. Also,

Is a clock value corresponding to the start point of the period of the synchronization signal.

을 구한다.Therefore, by substituting (X, Y) the clock value and the voltage magnitude in the primary or secondary measurement

.

와의 차이를 구한 후 이를 시간으로 변환한다. 이 시간이 동기 신호 주기의 시작점으로부터 현재까지 경과된 시간이다. 이를 가지고 시간 기록(timestamp)의 10밀리세컨드 이하의 시간을 보정한다.Then, the clock value of the current controller is obtained

And converts it into time. This time is the elapsed time from the start point of the synchronizing signal period to the present. This is used to compensate for timestamps that are less than 10 milliseconds in duration.

Therefore, the first controller through the Nth controllers 110-1 through 110-N proceed in the same process, and as a result, they know the starting point of the cycle of the external synchronization signal and calculate the elapsed time for each controller, And / or corrected. Thereby, all of the controllers 110-1 to 110-N can acquire precise time records on the same time axis.

100: Data synchronization system
110-1 to 110-N: First to Nth controllers
111: Server Process
112: Client process
410: external electronic circuit

Claims (14)

A data synchronization system comprising a time record for synchronizing data between a plurality of sensors disposed in a robot,
An external electronic circuit for generating a synchronizing signal; And
A plurality of controllers for generating time records in accordance with the time information of the synchronization signal or the own operating system and for synchronizing data with the time recording and unique identifier through communications between the server process and the client processor and updating the data according to the synchronization, Lt; / RTI &gt;
Wherein the plurality of controllers acquire the time record individually from the time information of the operating system in the case of a time longer than a second unit and acquire the time information by using the synchronization signal in the case of a time shorter than a second unit time. Data synchronization system.
The method according to claim 1,
Wherein the plurality of controllers simultaneously receive the synchronization signal to synchronize the reference points of the time recording.
The method according to claim 1,
Wherein the server process and the client process communication are communication between one client process and a plurality of server processes.
3. The method of claim 2,
Wherein the synchronization signal is an analog waveform of a triangle wave.
delete The method according to claim 1,
Wherein the second unit is one second.
The method according to claim 1,
Wherein the correction of the time recording is performed using the start point of the period of the synchronization signal.
8. The method of claim 7,
Wherein the start point of the period of the synchronization signal is a clock value calculated using a voltage magnitude, a rising and a falling of a waveform of the synchronization signal.
9. The method of claim 8,
Wherein the correction of the time recording is a value obtained by converting a difference between a clock value of the start point and a current clock value of the corresponding controller among the plurality of controllers into a time.
The method according to claim 1,
Wherein the plurality of controllers obtain the time record on the same time axis. The method according to claim 1,
Wherein the connection relationship between the server process and the client process is defined as a connection setting file including a server list, a server address according to the server list, and data item information.
The method according to claim 1,
Wherein the plurality of controllers execute only one server process and one client process, respectively.
The method according to claim 1,
Wherein the unique identifier is assigned to each of the plurality of controllers and data items.
A method of data synchronization in a data synchronization system, comprising a time record for synchronizing data between a plurality of sensors disposed in a robot,
The external electronic circuit generating a synchronization signal;
A plurality of controllers generating a time record according to the time information of the synchronization signal or the operating system;
The plurality of controllers generating data having the time stamp and unique identifier;
Synchronizing the plurality of controllers with each other through communication between a server process and a client processor; And
The plurality of controllers updating the data according to the synchronization,
Wherein the plurality of controllers acquire the time record individually from the time information of the operating system in the case of a time longer than a second unit and acquire the time information by using the synchronization signal in the case of a time shorter than a second unit time. Data synchronization method.

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